Method and variables
Formulas: σ = F / A; ε = σ / E; ΔL = ε × L₀.
- F — axial force
- A — cross-sectional area
- E — Young's modulus
- L₀ — original length
- ΔL — predicted elastic change in length
Worked example
A 1 m steel bar with a 100 mm² area, loaded axially with 10 kN, has a stress of 100 MPa. Using E = 200 GPa, its strain is 0.0005 and its elastic elongation is 0.5 mm.
When to use it
Use this for a first-pass, straight-member calculation when the load is axial, the cross-section is uniform and the material remains in its linear-elastic range.
Important limits
This tool does not evaluate yielding, plastic deformation, stress concentrations, bending, shear, buckling, fatigue, creep, temperature effects or structural code requirements. It is not a final design or safety check.
References
Related tools
Thermal Expansion Calculator · Pressure, Force and Area Calculator · Engineering Calculators
Frequently asked questions
How is elastic elongation calculated?
First calculate stress with σ = F / A. In the linear-elastic range, strain is ε = σ / E, then elongation is ΔL = ε × L₀.
What is Young's modulus?
Young's modulus, E, describes a material's stiffness in the elastic range. A higher value means less strain at the same stress.
Does the calculator check whether the part will fail?
No. It reports a linear-elastic estimate only. Yield, ultimate strength, buckling, fatigue, connections and code-required safety factors need separate checks.